Senior Migration Engineer - Health-tech (Java Spring Boot → Rust)

Senior Migration Engineer (Java Spring Boot → Rust)

📍 Berlin (Onsite every Thursday mandatory) 💰 Up to €80,000 🗣️ English (professional level required), German is a plus

About the Company

This is a healthtech company operating at scale, delivering technology that supports critical healthcare-related services and data-driven products. The platform plays a key role in enabling reliable, secure, and high-quality digital healthcare solutions.

The company is currently undergoing a high-risk, time-critical platform transformation while continuing to deliver live production services without disruption.

A legacy Java Spring Boot platform (Thymeleaf + Angular) is being migrated into a modern architecture using Rust, Flutter, and React — while preserving full functional parity across critical modules including content management, reporting, and billing.

Alongside this transformation, a parallel product line is operated in production, making stability, precision, and engineering discipline essential in a regulated, high-impact environment.

This is a fast-moving setting with a compressed delivery timeline (approximately 3 months shorter than originally planned), requiring strong ownership, clarity under ambiguity, and disciplined execution.

The Role

We are looking for a Senior Migration Engineer to take a leading role in the migration of core backend services from Java Spring Boot into Rust.

You will work at the heart of a complex system rewrite where correctness, stability, and business continuity are critical. The role involves deep analysis of legacy behaviour, extraction of implicit business logic, and building modern, production-ready services with zero tolerance for regression in critical workflows.

Key Responsibilities

• Lead migration of core services from Java Spring Boot to Rust

• Analyse legacy systems to extract and formalise implicit business logic

• Ensure functional parity across critical modules (billing, reporting, CMS)

• Design and implement APIs, schemas, and service boundaries for the new architecture

• Support staged migration strategies, including parallel-run and cutover planning

• Define and maintain parity checklists, runbooks, and acceptance criteria

• Debug and resolve complex production issues in business-critical flows

• Collaborate closely with product, QA, engineering, and DevOps teams

• Ensure high standards of testing, observability, and production readiness

Required Skills & Experience

• Proven experience delivering production migrations from Java-based systems (Spring Boot) to modern architectures

• Strong hands-on engineering experience with Java Spring Boot

• Solid production-level experience with Rust (or demonstrated ability to transition at speed)

• Experience working with legacy systems and decomposing complex business logic

• Strong understanding of API design, schema evolution, and system correctness

• Ability to define clear acceptance criteria from ambiguous requirements

• Experience delivering under tight deadlines without compromising system reliability

• Strong cross-functional communication and collaboration skills

Nice to Have

• Experience with billing or reporting systems

• Exposure to dual-run / parallel-run migration strategies

• Experience with event-driven or asynchronous architectures

• Previous mentoring or informal technical leadership experience

What You’ll Be Working On (Challenges We’re Solving)

• Reducing migration cycle time under compressed delivery timelines

• Minimising cross-team integration friction in a fast-moving environment

• Preventing regressions in complex, business-critical workflows

• Safely retiring legacy components while maintaining live system stability

Why Join This Team

This is a high-impact engineering role within a healthtech environment, where engineering decisions directly influence the reliability and quality of healthcare-related digital services.

You’ll work in a focused engineering team of around 12 people, with strong ownership and the opportunity to shape how critical systems are rebuilt from the ground up.

We are also actively working to improve diversity within the engineering team and encourage applications from underrepresented groups in tech.